@Tihomir Turn these on: Post the following: and this:

@Tihomir No, once rebooted and the logs are gone. You have an option to send them by e-mail or save them locally - probably you won't find there anything related to the issue. Set your security...

If you suspect any misconfiguration then post the settings in question here (just cover any SSIDs and passwords) and I can review them.

When talking about FW, you can't be sure of anything - it's like a black box for the user - it could be well or poorly written. What points to the cable issue is your test earlier: "I also plugged...

@Tihomir If you think that the problem is overheating, try to place the router in a well ventilated place and test if that could be excluded. Judging by the AX73 specs the devices, that you are...

Well, you have to test that and observe. If the issue persists, the next thing would be replacing the cable, if that's possible.